Mitochondrial dysfunction and accumulation of oxidative damage have been implicated to be the major factors of aging. However, data on age-related changes in activities of mitochondrial electron transport chain (ETC) complexes remain controversial and molecular mechanisms responsible for ETC dysfunction are still largely unknown. In this study, we examined the effect of aging on activities of ETC complexes and oxidative damage to proteins and lipids in cardiac mitochondria from adult (6-month-old), old (15-month-old) and senescent (26-month-old) rats. ETC complexes I-IV displayed different extent of inhibition with age. The most significant decline occurred in complex IV activity, whereas complex II activity was unchanged in old rats and was only slightly reduced in senescent rats. Compared to adult, old and senescent rat hearts had significantly higher levels of malondialdehyde, 4-hydroxynonenal (HNE) and dityrosine, while thiol group content was reduced. Despite marked increase in HNE content with age (25 and 76 % for 15- and 26-month-old rats, respectively) Western blot analysis revealed only few HNE-protein adducts. The present study suggests that non-uniform decline in activities of ETC complexes is due, at least in part, to mitochondrial oxidative damage; however, lipid peroxidation products appear to have a limited impact on enzyme functions.

Abstract. Mitochondrial electron transport chain is thought to be a major source of reactive oxygen species (ROS) during aging. However, this view is supported mainly by accumulation of mitochondrial oxidative damage with age and the exact sites of ROS formation remains unknown. In the present study, we measured rate of ROS formation using 2' ,7'-dichlorofluorescein (DCF) probe in cardiac mitochondria from adult (6-month-old), old (15-month-old) and senescent (26-month-old) rats. In mitochondria oxidizing complex II substrate, succinate, the rate of ROS formation progressively increased with age. In the presence of complex I inhibitor rotenone or complex III inhibitor antimycin A, the rate ROS formation significantly decreased, but even the combination of inhibitors could not fully prevent generation of ROS. Age-dependent increase of ROS formation was accompanied by a loss of thiol groups, tryptophan degradation and increased lipid peroxidation. These data suggest that in addition to complex I and complex II other mitochondrial sites can contribute to accelerated ROS generation and oxidative damage during aging.

SUMMARYNanoparticles exist for a long time as both inorganic and organic parts of nature. Recently, massive expansion of nanotechnologies is evidenced, together with intentional production of new nanoparticles which have not been in contact with living organisms until now. Besides obvious positive aspects, potential threats related to their exposure should be taken into consideration. Unique physical-chemical properties of nanoparticles cause a high bioactivity following their intake (through air, ingestion and skin) and unrestricted spread in exposed organs. Primary effects of nanoparticles on cellular level represent oxidative stress and reactions leading to apoptosis, autophagocytosis and necrosis. Number of studies indicating contribution of nanoparticles to numerous disorders has been recently increasing. However, detailed mechanisms of health effects are not well known. Similarly, there is insufficient information on life cycle of nanoparticles in the environment. Research in this field as well as legislation is behind rapid development and use of nanotechnologies. Considering absence of mandatory exposure limits and other protective measures, nanomaterials represent a potential threat for population health. Recommendations and guidelines of international institutions can contribute to deal with situation, however, passing of effective legislation both on national and European level is urgently needed.

Objective: The aim of the study was to analyse the occurrence of lead in selected samples of fruit distilled spirits for own consumptions in terms of possible contribution to the occurrence of alcohol-attributable diseases. Methods: In a pilot study, we analysed 18 samples of fruit spirits for own consumption. Most of the samples were distilled in the local growing distilleries in the Žilina Region with exception of 3 samples collected in the Trnava Region (one of them was of Hungarian origin). Sample preparation included previous mineralization with use of microwave decomposition system Multiwave 60 50 Hz. The samples were analysed by atomic absorption spectroscopy with graphic furnace (AAS GBC XplorAA 5000 with GF 5000). Results: The average ethanol level in our samples was higher in comparison with distributed spirits. We detected lead in all samples. In two of them the concentration was lower than the limit of quantitation (LOQ). The highest lead concentrations were observed in plum spirit from Hungary (581.0 μg/l), and in grape spirit made in the Trnava Region (466.3 μg/l). Conclusions: Lead is a widespread contaminant of fruit spirits prepared for own consumption. Taking into consideration its common occurrence and possible multiplicative effect with ethanol, we can assume that lead can contribute to the occurrence of several alcohol-attributable chronic diseases. Due to the insufficient information in this field, our results provide significant insight into the issue and present an important starting point for further research.

Objectives: The purpose of this study was to identify personal variables and nonoccupational risk factors for carpal tunnel syndrome and to analyse the strength of association of these factors.Methods: We performed a case-control study with 162 cases and 300 controls. We studied consecutive patients with an electrophysiologically confirmed diagnosis of symptomatic carpal tunnel syndrome. Univariate analysis was performed in the case group and control comparing them for presence of various risk factors. Multivariate analysis was carried out through logistic regression.Results: The mean BMI and age were greater in the case group than in the control. Multivariate analysis showed that BMI (OR = 1.05, 95% CI = 1.01-1.11) and arterial hypertension (OR = 4.63, 95% CI = 2.88-7.44) were the only factors significantly associated with carpal tunnel syndrome. The age, cigarette smoking and alcohol drinking were at the edge of significance.Conclusions: Carpal tunnel syndrome is the most common peripheral neuropathy and has been related to occupational activities in some but not all studies. Clarifying this relationship has important implications for workers' compensation systems. Based on our findings, BMI and arterial hypertension are considered to be the most significant risk factors of carpal tunnel syndrome in our study.